The present invention relates to machines for winding (paying out or collecting) webs of paper or the like from or onto the cores of reels or analogous carriers of convoluted web or strip material, and more particularly to improvements in apparatus which are used in such machines to support the reels during winding. Still more particularly, the invention relates to improvements in reel supporting apparatus of the type wherein the two ends of the axial hole in the reel which is ready to be rotated receive two coaxial trunnions and the end faces of the reel on the trunnions are disposed between two stops which are designed to hold the reel against excessive axial movement.
As a rule, a reel which includes convoluted paper has a cylindrical sleeve-like core consisting of cardboard or the like. The aforementioned trunnions of the apparatus which supports the reel in a winding machine extend into the end portions of the core from opposite axial ends of the reel. The trunnions are often preferred over a shaft which extends all the way through the core because it is simpler to mount a reel-carrying core on or to remove an empty core from a pair of coaxial trunnions which are movable axially toward and away from each other. Each trunnion and the associated stop is movable axially by a motor (e.g., an electric motor) or by a hydraulic or pneumatic drive so that the reel is placed between the two stops while the trunnions are held apart, and the trunnions are thereupon moved toward each other to penetrate into the respective end portions of the core. As a rule, each of the trunnions and the associated stop is movable by a discrete drive, i.e., each unit including a trunnion and the associated stop can be moved relative to the other unit.
During winding, it is often necessary to shift the entire reel axially of the trunnions, i.e., to move both trunnions in the same direction while maintaining the distance between the stops at a given or constant value. In other words, it is desirable to provide means for ensuring that both trunnions move in synchronism in a direction to the right or to the left, depending on the desired direction of axial displacement of the reel in the winding machine. However, and since the aforementioned units have discrete drives, malfunctions are likely to occur, for example, if one of the units remains at a standstill while the other unit moves away from the one unit or when the other unit moves at a speed exceeding the speed of the one unit. This brings about the danger of completely extracting one or both trunnions from the respective end portion or portions of the core with the result that the thus released reel can damage the machine and/or cause injury to the attendants.